Lie Detector Looks Inside Your Brain

MRI May Check Truthfulness, But Is It More Accurate Than Polygraphs?

(AP) 
Her worries multiply if fMRI evidence starts showing up in the courtroom. For one thing, unlike the technical data from a polygraph, it can be used to make brain images that look simple and convincing, belying the complexity of the data behind them, she said.

"You show a jury a picture with a nice red spot, that can have a very strong impact in a very rapid way.... We need to understand how juries are going to respond to that information. Will they be open to complex explanations of what the images do and do not mean?"

It didn't take any jury to find the truth in my case.

"We nabbed ya," George said after sending me the results of my scan. "It wasn't a close call."

I was ratted out by the three parts of my brain the technique targets. They'd become more active when I lied about taking the watch than when I truthfully denied taking the ring.

Those areas are involved in juggling the demands of doing several things at once, in thinking about oneself, and in stopping oneself from making a natural response — all things the brain apparently does when it pulls back from blurting the truth and works up a whopper instead, George said.

Of course, nobody is going to make me or anybody else climb into an fMRI scanner every time they want a statement verified. The procedure is too cumbersome to be used so casually, George says.

But he figures that if a perfect lie detector were developed, that practical consideration might not matter. The mere knowledge that one is available, he said, might provoke people to clean up their acts.

"My hope," George said, "would be that it might make the world operate a little bit more openly and honestly."